This invention relates a stabilized fluid pressure regulator and particular to a fluid regulator including a leakport orifice having a pressure responsive closure unit and having a leakage orifice unit, and to the method of forming precise orifice units.
As fully set forth in the U.S. Pat. No. 4,315,520 whereby issued Feb. 16, 1982 to the present inventor, leakport orifice regulators having a pressure responsive closure elements are well known and used in providing a regulated fluid pressure or flow in response to an input signal. Closure elements generally may include a diaphragm, a bimetal sensor and the like. The system encounters a relatively unstable condition as the gap in the leakport orifice moves to a close spaced relation, establishes a minimal gap for the air flow, resulting in vibration of the closure member. The subject patent discloses a particularly satisfactory solution which minimizes the above adverse characteristics. As fully disclosed therein, forming of the orifice unit with minute notches in a sharp ended planar orifice creates a continuous leakage path and a minimal flow is maintained under all conditions. Further, as the flow gap is reduced, the leakage flow forms a progressively increasing proportion of the total flow. The system results in essentially eliminating the vibration characteristic previously encountered and a stable output pressure, which is free of audible noise or the like.
Although the specially formed orifice has found substantial commercial acceptance, a demand continues for an even more stable structure. Thus, as the orifice is closed, the diaphragm is squeezed onto the orifice and there is a change in the leakage flow. This results in some change in the characteristics.
Orifices, which have been heretofore made through molding are generally limited to orifice openings on the order or 0.030 inches of greater, the molding apparatus includes a pin member corresponding to the diameter of the hole and an opposed core member which is provided with an aperture substantially the same as the diameter of the pin. The pin is telescoped into the hole and the orifice unit is molded about such assembled cores. However, in the telescoped construction, mere flashing tends to occur. The flash creates a flexible closure which responds in the flow to move into the orifice under operating conditions. Such structure dramatically changes the characteristic of the orifice and significantly reduces the quality of the flow control device. Small orifices have generally involved jeweled orifices. In forming of jewel orifices, the orifice itself is constructed using the laser or other effective cutting methods for forming the orifice opening. The orifice is formed however as a separate element and then mounted in a body or housing for coupling and connection into a system such as a connecting tube unit, a housing or the like. Thus, it is not formed as a self contained element which can be connected directly into a fluid device or to connecting tubes for connections in a fluid circuit.